\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes,}
\begin{document}
\small
\begin{tikzpicture}[>=stealth, thick]
  \draw[dashed, ->](0,0)--(13,0) ;
  \node at (13,-.5){选定的正方向};
  \fill (3,0) circle[radius=2.5pt];
  \draw[very thick, ->](3,0)--node[above]{$F_4=-\qty{5}{N}$}(1,0);
  \fill (3.5,0) circle[radius=2.5pt];
  \draw[very thick, ->](3.5,0)--node[above]{$F_3=\qty{7}{N}$}(6.3,0);
  \fill (9,0) circle[radius=2.5pt];
  \draw[very thick, ->](9,0)--node[above]{$F_2=-\qty{5}{N}$}(7,0);
  \fill (10,0) circle[radius=2.5pt];
  \draw[very thick, ->](10,0)--node[above]{$F_1=\qty{5}{N}$}(12,0);
\end{tikzpicture}
\end{document}